<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*id选择器*/
        #p1{color: red}
        /*类选择器*/
        .c1{color: green}
        /*分组选择器*/
        a,#p1,.c1{
            background-color: yellow;
        }
        /*属性选择器*/
        input[type='text']{color: red}
        input[type='password']{background-color: green}
        /*任意元素选择器*/
        *{
            /*边框: 粗细 边框样式 颜色*/
            border: 1px solid red;
        }
    </style>
</head>
<body>
<input type="text">
<input type="password">
<a href="">超链接</a>
<p id="p1">苹果</p>
<p>香蕉</p>
<p class="c1">橘子</p>
<div>电视</div>
<div>冰箱</div>
<div class="c1">洗衣机</div>
</body>
</html>